2008/08/31 by Antonaldo Diaferio, Luisa Ostorero · 2 citations
Physics and Astronomy · #Adiabatic process #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Conformal gravity #Conformal map #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy rotation curve #Gravitation #Gravitational potential #Parametrization (atmospheric modeling) #astro-ph #gr-qc
paper · pdf · doi:10.1111/j.1365-2966.2008.14205.x
10 pages, 5 figures, MNRAS in press. A few clarifications included, according to referee's suggestions
arxiv created 2008/11/06 · openalex publication_date 2009/01/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We run adiabatic N-body/hydrodynamical simulations of isolated self-gravitating gas clouds to test whether conformal gravity, an alternative theory to general relativity, is able to explain the properties of X-ray galaxy clusters without resorting to dark matter. We show that the gas clouds rapidly reach equilibrium with a density profile which is well fitted by a β-model whose normalization and slope are in approximate agreement with observations. However, conformal gravity fails to yield the observed thermal properties of the gas cloud: (i) the mean temperature is at least an order of magnitude larger than the observed and (ii) the temperature profiles increase with the square of the distance from the cluster centre, in clear disagreement with real X-ray clusters. These results depend on a gravitational potential whose parameters reproduce the velocity rotation curves of spiral galaxies. However, this parametrization stands on an arbitrarily chosen conformal factor. It remains to be seen whether a different conformal factor, specified by a spontaneous breaking of the conformal symmetry, can reconcile this theory with observations.